1. Field of the Invention
The invention relates to a high-speed operational amplifier circuit, and more particularly to a high-speed operational amplifier circuit having high linearity and design freedom.
2. Description of the Related Art
Using high-speed operational amplifier is a trend in high-frequency (for example, several GHz) applications. When designing a high-speed operational amplifier, transconductance(s) may be used in the operational amplifier circuit to extend operation bandwidth of the operational amplifier. However, it may be power inefficient for an application bandwidth larger than several GHz since the parasitic poles may cause the operational amplifier to become unstable and more current may be needed to stabilize it.
Since using the high-speed operational amplifier is a trend in high-frequency (for example, several GHz) applications, a novel high-speed operational amplifier circuit which is more stable and has lower power consumption than the conventional designs, and which further has high linearity and design freedom, is highly desired.